WO2014114879A2

WO2014114879A2 - Method and unit for dry cleaning textile articles using a composite solvent and for recycling the used composite solvent for re-use

Info

Publication number: WO2014114879A2
Application number: PCT/FR2014/050120
Authority: WO
Inventors: Alfred Testa; Jean-Philippe TESTA
Original assignee: Arcanes Industries
Priority date: 2013-01-22
Filing date: 2014-01-22
Publication date: 2014-07-31
Also published as: WO2014114880A3; WO2014114880A2; EP2948585A2; US20160010269A1; CN104955999B; WO2014114879A3; FR3001235B1; CN104955999A; FR3001235A1

Abstract

The invention relates to a method for dry cleaning textile articles using a composite solvent comprising multiple components and for recycling the used composite solvent for re-use, said method including: e) a dry cleaning cycle in which the textile articles to be cleaned are brought into contact with the composite solvent; f) recovery of the used composite solvent contaminated by water and dirt at the end of the dry cleaning cycle; g) treatment of the used composite solvent such as to remove at least the water and dirt; h) recycling of at least part of the composite solvent treated in step (c) for use in another dry cleaning cycle. The method is characterised in that it also comprises a step (e) of re-adjusting the composition of the composite solvent recycled in step (d) in which: the part of the component(s) of the composite solvent that was lost during step (c) is determined, and at least said determined part of the component(s) of the composite solvent that was lost during step (c) is incorporated into the composition of the composite solvent recycled in step (d).

Description

METHOD AND INSTALLATION FOR DRY CLEANING

OF TEXTILE ARTICLES USING A COMPOSITE SOLVENT AND RECYCLING THE COMPOSITE SOLVENT USED FOR

REUSE

Description

Technical Field of the Invention

The invention relates to a method and a facility for dry cleaning textile articles using a composite solvent comprising several components and recycling the spent composite solvent for reuse.

The technical field of the invention may, in general, be defined as that of dry cleaning techniques for clothing, textiles, fabrics and the like, and more particularly techniques for recycling contaminated solvents for reuse.

State of the art Dry cleaning processes for textile articles use an organic solvent in the washing phase. The latter may be a mono-component solvent such as perchlorethylene which is classified as possible carcinogen (category 3) by the European Union and which is now banned in France, or a composite solvent comprising several components such as aqueous ether solutions. propylenes glycols (see for example US patent documents 6,273,919 (Hayday, WA), US 7,144,850 (Galick et al.)); C10-C13 aliphatic hydrocarbon mixtures such as Ecosolv® solvent marketed by Chevron Phillips®; compositions comprising a volatile siloxane and an organic surfactant, and optionally water (see US 6521580 (Perry et al.)); or the compositions comprising a siloxane solvent and / or a hydrocarbon solvent and an enhancer compound of a KB value of the composition (US2012 / 0085634 (Douglas et al.).

Typically, a method of dry cleaning textile articles comprises the steps of: (a) contacting the textile articles to be cleaned with the liquid solvent in a washing and drying machine provided with a cleaning basket and stirring in rotation about a horizontal axis; (b) subjecting the textile articles in the presence of the solvent to rotational (alternating-inverted) movements to ensure the removal of contamination contaminating the textile articles; (c) extracting the spent solvent from the basket by pumping, (d) subjecting the cleaned textile articles to centrifugation to extract as much of the spent solvent as possible, and (e) removing the residual solvent by vaporization by injecting a stream of hot air through the textile articles. At the end of a dry cleaning cycle, the recovered solvent is most often contaminated by different kinds of soiling, namely (i) insoluble soils such as dust, balls or strands isolated from textile fibers and dye pigments detached from cleaned items and (ii) soluble soils such as fats, fatty acids from perspiration, dyes, etc. The recovered solvent is also very often contaminated by the water that comes from the relative humidity of the air, the moisture (eg sweat) contained in the textile articles to be cleaned, and / or the water introduced into the water. cleaning apparatus following pretreatment operations of textile articles, for example with aqueous stain removers or aqueous pre-scrubbers. However, for reasons of public health and protection of the environment, but also the cost of the solvent, it is not desirable to reject the spent solvent. It is thus common to recycle, especially by distillation, the solvent used in the same dry cleaning machine for the purpose of reusing it in one or more new cycles of dry cleaning.

Document US2012 / 0085634 (Douglas et al.) Discloses a process for dry cleaning textile articles using a composition consisting of a dry cleaning agent comprising a siloxane solvent, a hydrocarbon solvent or their mixture and an amplifier compound, which makes it possible to increase a KB value of said composition. This process also includes the recycling by distillation of the used cleaning composition for the purpose of reuse. However, this process requires the implementation of a first atmospheric distillation consuming energy (at more than 100 ° C) but especially time, during which water, azeotropic and other volatile compounds are eliminated, followed by a second distillation under reduced pressure (at about 150 ° C) during which the dry cleaning agent and the boosting compound are recovered and redirected to the storage tank for reuse. This process is difficult to implement for recycling for reuse of composite solvents whose components are likely to degrade or hydrolyze at such temperatures or form separate azeotropes between them and / or with water making distillation complicated and difficult to manage in the dry cleaning machine. Thus, in view of the foregoing, it is an object of the present invention to provide a method and a dry-cleaning apparatus for textile articles using a composite solvent comprising a plurality of components, which also enables regeneration of satisfactory solvent used for a second use. The present invention also aims to provide such a method and such a facility that are simple and safe and that can adapt to different composite solvents.

Disclosure of the invention.

The solution proposed by the invention is a method of dry cleaning textile articles using a composite solvent comprising several components and recycling the spent composite solvent for reuse. This process comprises:

a) a dry cleaning cycle comprising contacting the textile articles to be cleaned with the composite solvent,

b) the recovery of the spent composite solvent contaminated with water and dirt after the dry cleaning cycle,

c) treating the spent composite solvent so as to remove at least water and dirt,

d) recycling at least a portion of the composite solvent treated in step c) for use for at least one further dry cleaning cycle.

This method is remarkable in that it further comprises a step e) of rebalancing the composition of the composite solvent recycled in step d) in which:

the part of the component (s) of the composite solvent which has been lost in step (c) is determined,

at least the determined part of the component or components of the composite solvent which has been lost in step c) is incorporated in the composition of the composite solvent recycled in step d).

The advantages of the present invention are that the process is applicable to currently available dry cleaning composite solvents, especially composite solvents whose components can form between them and / or with water separate azeotropes and thus make the regeneration by distillation of the spent composite solvent complicated and difficult to manage in the dry cleaning machine. The method of the invention also has the advantage of allowing the reuse of the recycled composite solvent under optimal conditions. Indeed, thanks to the rebalancing step e) the recycled composite solvent finds at least the part of the component or components or at least the component or components that were lost during the treatment step c) and if appropriate in the recycling step d), step c) can be carried out for example by filtration followed by a conventional distillation, preferably under vacuum, then a decantation; or preferably a fractional distillation, preferably under vacuum.

Other preferred features of the invention are listed below, each of these characteristics being able to be considered alone or in combination with the remarkable characteristics defined above:

^■ Preferably, the treatment of the composite solvent used in step c) is carried out by fractional distillation.

^■ Preferably, the fractional distillation of spent composite solvent is carried out so as to:

removing a fraction F1 head shorter representing 15% w / w _S worn oivant composite and containing at least water and one or more azeotrope formed between the water and one or more components of the composite solvent, and

obtain an intermediate fraction F2 representing more than 75% w / w _S oivant composite and spent solvent containing the composite dry cleaning decreased by at least a portion, by weight, of one or more of its components, which portion has been lost in treatment step c).

^■ In step c) prior to fractional distillation, the composite solvent is used filter to remove the insoluble soil. ^■ The composite solvent used for the dry cleaning of textile articles comprises at least:

from 40% to 80% w / w _S oivant composite monomethyl ether of dipropylene glycol, 5% to 40% w / w _S oivant composite of an amphiphilic solvent A having the following formula: R- (0-C3H6) _n -OH (I) wherein n is an integer of 1 or 2, and R is a C ₃ or C ₄ alkyl group,

from 10% to 40% w / w _S composite composite of a dibasic ester B selected from the group consisting of dimethyl succinate, dimethyl glutarate, dimethyl adipate and mixtures thereof, and

- from 0% to 10% w / w _S composite composite of additional components.

^■ The spent composite solvent to be recycled is contaminated with at least 0.5% by weight of the spent composite solvent. ^■ The F1 overhead fraction removed by fractional distillation in step c) is distilled at a temperature less than 82 ° C and a pressure of 65 mBar and comprises at least water, dipropylene glycol monomethyl ether, and, if optionally an amphiphilic solvent A 'having the following formula: R'-O-C ₃ H 6 -OH () in which R' represents a C ₃ or C ₄ alkyl group,

^■ The intermediate fraction F2 recovered by fractional distillation in step c) distilled at a temperature above 83 ° C and under a reduced pressure of 65 mBar. ^■ Part to incorporate the composition of the composite solvent recycled to step d) comprises at least dipropylene glycol monomethyl ether, and optionally an amphiphilic solvent A 'having the formula R'-0-C ₃ H6 OH (Γ) in which R 'represents a C ₃ or C ₄ alkyl group. ^■ The F1 fraction removed in step c) can be recovered in a drain tank, and after N dry cleaning cycles, be subjected to a fractional distillation, fractional distillation which is carried out so as to eliminating a head fraction F'1, said head fraction F'1 containing a preponderant amount of water; and recovering a fraction F'2, which fraction F'2 is intended to be added, before step e) of rebalancing, to the intermediate fraction F2 collected after the cycle N of dry cleaning.

^■ The process of the invention further comprises a step of analyzing the composition of the recycled composite solvent (or intermediate fraction F2) and determining the amount of the components to be incorporated in said composition in view of the balance.

According to another aspect, the present invention also relates to an installation for the dry cleaning of textile articles using a composite solvent comprising several components, said installation comprising:

a dry cleaning chamber configured to mix, during a cleaning cycle, the textile articles to be cleaned with the composite solvent,

a device for recovering the spent composite solvent after a cleaning cycle,

a treatment device for removing water and dirt and recycling at least a portion of the spent composite solvent for use in another dry cleaning cycle,

said installation being remarkable in that it further comprises a device for rebalancing the composition of the recycled composite solvent, which device comprises:

means for determining the portion of the component (s) of the composite solvent that was lost in step c),

means for incorporating into the composition of the composite solvent recycled in step d) at least the determined part of the component or components of the composite solvent which was lost in step c). Description of the figures.

Other advantages and features of the invention will appear better on reading the description of a preferred embodiment which follows, with reference to the accompanying drawings, given by way of non-limiting example and in which:

Figure 1 schematically shows an installation according to the invention.

Figure 2 shows schematically a variant according to the invention.

Embodiments of the invention

The present invention is based on the experimental finding that used composite solvents recovered after a first cycle of dry cleaning textile articles, recycled, especially by distillation, and reused in a new cleaning cycle, are less effective for removal hydrophilic soiling and / or hydrophobic soiling as the starting composite solvents. This decrease in performance can be explained by the fact that during the recycling operations, especially by distillation, the composite solvents lose one or more of their components or part of one or more of their components. Such a loss of component (s) or part of component (s) induces a change in the composition of recycled composite solvents, and therefore a significant change in dry cleaning properties. The Applicant has solved the problem of declining performance of recycled composite solvents by determining the part of the component (s) of the composite solvent which has been lost during the treatment operations aimed at removing at least water and dirt, and by incorporating into the recycled composite composition composition at least the part of the component (s) that has been lost during the recycling operations. The part of the component (s) to be incorporated into the composition of the recycled composite solvent can be determined, for example, by laboratory pre-tests carried out on the composite solvent to be used for the dry cleaning of textiles, comprising, for example, the determining the initial composition of the composite dry cleaning solvent; and, knowing the optimum conditions for performing dry cleaning and recycling operations with this composite solvent, the determination of the component (s) or part of the component (s) of the composite solvent which may be lost during the recycling operations. The part of the component (s) to be incorporated into the composition of the recycled composite solvent can also be determined in real time by any method capable of analyzing the chemical composition of the recycled composite solvent, and to make a comparison between the analyzed composition and that of the composite solvent. to deduce the lost component (s) and their contents in weight or in volume. By way of nonlimiting example of chemical analysis methods, mention may be made of infra-red spectroscopy or gas chromatography (GPC).

In this text, we mean:

"Composite solvent" means a solvent containing at least two components that plays an essential role in imparting dry cleaning properties of textile articles.

"Dry cleaning" means the cleaning in which the composite solvents act as a solvent or a cleaning liquid to replace the water.

"Textile articles" means objects used in a personal or professional setting (eg various industries, hospitals, etc.), and made from natural fibers such as cotton, wool, flax, silk or otherwise, and / or from synthetic fibers such as nylon, polyamide, acrylic, polyester, acetate, viscose, or other. Examples of textile articles include shirts, pants, sweaters, jackets, coats, tablecloths, blankets, sheets, towels, duvets, leather clothing, suede, etc. "Soil" means the soil, hydrophilic or hydrophobic, soluble in the composite solvent, and soils that are insoluble therein such as dusts, balls or strands of textile fibers isolated and dye pigments detached from cleaned or other articles.

- "hydrophobic soiling" means soiling contaminating textile articles and generally consisting of organic materials or materials which are not water-soluble and insoluble therein. As non-limiting examples of "hydrophobic soiling" include fat, oil, mayonnaise, mustard, body oils, tar stains or engine oil etc.

'Hydrophilic soiling' means the soiling contaminating textile articles and consisting mainly of organic or inorganic matter which has certain affinities with water and which is wholly or partially soluble therein. As non-limiting examples of "hydrophilic soiling", mention may be made of body fluids such as perspiration, blood, urine, water-soluble food products such as sugar, salt, chocolate, fruit juice, tea, coffee, etc.

"Major part" means according to the invention the initial composition of the composite solvent used for the dry cleaning of textile articles, reduced by at least a portion, by weight, of one or more components of the composite solvent lost during the treatment and recycling steps of the spent composite solvent.

The percentages, contents and ratios used below are all given relative to the total weight of the composition "w / w composite w _/ w composite", unless otherwise indicated.

Method of dry cleaning textile articles and recycling used composite solvent

The present invention is aimed primarily at a method of dry cleaning textile articles using a composite solvent comprising several components and recycling spent composite solvent for reuse. Advantageously, this process comprises:

b) recovering the spent composite solvent contaminated with water and dirt at the end of the dry cleaning cycle,

d) recycling at least a portion of the composite solvent treated in step c) for use in another dry cleaning cycle,

e) determining the part of the component (s) of the composite solvent that was lost in step c), and incorporating into the composition of the recycled composite solvent in step d) at least the determined part of the components of the composite solvent which was lost in step c).

By way of example of composite solvents comprising several components and suitable for the dry cleaning of textile articles according to the present invention, mention may be made of the composite solvent S comprising at least:

dipropylene glycol monomethyl ether (DPM),

an amphiphilic solvent A corresponding to the following formula: R- (O-C3H6) _n -OH (I) in which n is an integer equal to 1 or 2, and R is a C ₃ or C ₄ alkyl group, and

a dibasic ester B selected from the group consisting of dimethyl succinate, dimethyl glutarate, dimethyl adipate and mixtures thereof.

This composite solvent S has recently been developed by the Applicant who has been able to demonstrate that it exhibits a high cleaning power with respect to hydrophobic soils (especially fats), but also with respect to hydrophilic soils (water-soluble organic or mineral materials) that may appear on textile articles. The Applicant has also demonstrated that such a composite solvent can be adapted to the type of soils (hydrophobic or hydrophilic) and the type of textile articles to be dry cleaned by varying the proportions of the three essential ingredients namely dipropylene glycol monomethyl ether, amphiphilic solvent A and dibasic ester B. The Applicant also noted that this composite solvent also has the advantage of maintaining, in solution or suspension, the liquid or solid dirt extracted during the dry cleaning operation thus avoiding their redeposition on the cleaned textile articles.

This composite solvent S can advantageously replace perchlorethylene (PERC) which is classified as a possible carcinogen (category 3) by the European Union and which is now banned in France for use in dry cleaning machines.

The Applicant has yet been able to demonstrate that the best dry cleaning results have been obtained with the composite solvents S comprising: (i) dipropylene glycol monomethyl ether (DPM), dipropylene glycol mono- / 7-butyl ether (PnB ) and dibasic ester DBE; (ii) dipropylene glycol monomethyl ether (DPM), dipropylene glycol mono- / 7-butyl ether (DPnB) and dibasic ester DBE; or (iii) dipropylene glycol monomethyl ether (DPM), dipropylene glycol mono- / e-7-butyl ether (DPtB) and dibasic ester DBE; or (iv) dipropylene glycol monomethyl ether (DPM), dipropylene glycol mono- / 7-butyl ether (DPnB), dipropylene glycol mono- / 7-propyl ether (DPnP), and dibasic ester DBE; or (v) dipropylene glycol monomethyl ether (DPM), dipropylene glycol mono- / 7-butyl ether (DPnB), propylene glycol mono- / 7-butyl ether (PnB), and dibasic ester DBE.

Note: The preferred dibasic ester (DBE) according to the invention is the dibasic ester Rhodiasolv® RPDE marketed by Rhodia. This composite solvent S (or these composite solvents) may advantageously also comprise all kinds of additional components usually used in the dry cleaning field. For example, Additional components may be selected from antioxidants, disinfectants, fragrances and mixtures thereof. These additional components may be present in the composition according to the present invention in an amount between 0.001% and 10% w / w _C om _P osition without substantially affecting its advantageous properties.

By way of example of anti-oxidizing agents (or stabilizers), mention may be made of 2,6-di-f-butyl-methylphenol (BHT) and 2-hexyl-butyl-4-hydroxyanisole. (2-BHA) and 3-B-butyl-4-hydroxyanisole (3-BHA) or mixtures thereof. Such antioxidant agents have the function of preventing or reducing or retarding possible formation of peroxides.

By way of examples of disinfecting agents, mention may be made of quaternary ammonium salts, aldehydes, phenol derivatives, halogenated compounds (eg iodinated compounds), alcohols or others. Such disinfecting agents will have the role of allowing a disinfecting action of textile articles to be cleaned, including household, medical or veterinary laundry. They also have a cleaning action of the enclosure dedicated to dry cleaning.

A preferred composite solvent S for carrying out the method of dry cleaning articles according to the present invention comprises:

from 40% to 80% w / w _S composite composite of dipropylene glycol monomethyl ether, from 5% to 40% w / w _S composite composite of an amphiphilic solvent A corresponding to the following formula: R- (O-C3H6) _n- OH (I) wherein n is an integer of 1 or 2, and R is a C ₃ or C ₄ alkyl group,

from 0% to 10% w / w composite compound of additional components.

Such a composite solvent S has the further advantage that it can be prepared by any mixing method known to those skilled in the art, from non-toxic components, classified as readily biodegradable, non-toxic expensive and commercially available. It is advantageously in the form of a clear and colorless liquid and can be packaged, in an anhydrous state, in any container capable of receiving a liquid, such as, for example, a storage tank made of steel or plastics such as polyethylene. and polypropylene.

However, the Applicant has noted that the use of such a composite solvent S in the form of an aqueous solution containing more than 8% w / w _S composite oivant s of water, do not lead to an optimum dry cleaning.

Step a) of the process according to the present invention can be carried out by any dry cleaning method known to those skilled in the art. In general, textile articles are: i) placed in a washing and drying machine (known to those skilled in the art) comprising for example a sealed enclosure which is provided with a rotating perforated drum and which is connected to a solvent circuit comprising a solvent circulation device, ii) contacted with the composite solvent, for example by immersion, iii) stirred in the composite solvent in rotational (alternating-inverted) movements to allow the dissolution of contaminating soils textile articles, iv) spin-dried to extract as much of the spent composite solvent as possible, and dried v) to remove the residual solvent, for example by injecting a stream of hot air through the textile articles.

In practice, the stirring phase iii) can be carried out at a temperature ranging from 15 ° C to 60 ° C depending on the composite solvent used and the textile articles to be cleaned. This brewing phase iii) can be repeated several times, for example twice. The hot air injected during the drying phase v) has a temperature above 40 ° C, preferably between 60 ° C and 80 ° C, depending on the composite solvent used and the textile articles to be cleaned. At the end of this dry cleaning cycle textile articles are obtained which are free of their stains and the spent composite solvent.

In practice, the spent composite solvent is recovered in step b), on the one hand, by pumping in the spinning step iv) and, on the other hand, by cooling the vapors generated during the step of drying v).

The solvent thus recovered is generally contaminated with various kinds of soiling, namely (i) insoluble soils such as dusts, balls or strands isolated from textile fibers and dye pigments detached from the cleaned articles and (ii) soiling soluble, hydrophilic or hydrophobic, such as fats, fatty acids from perspiration, etc. At this stage, the spent composite solvent recovered is also contaminated with water which comes from the relative humidity of the air and / or moisture (eg sweat) contained in the textile articles to be cleaned, and / or or the water introduced into the cleaning apparatus following pre-treatment operations of the textile articles, for example with aqueous stain removers or aqueous pre-scrubbers.

By way of example, the preferred composite solvent S developed by the Applicant (described above) is contaminated at this stage by at least 0.5% w / w composite water, in particular by at most 5%. w / w _s composite oivant s of water, as well as insoluble soil and soluble soil.

Step c) of the process of the present invention aims to purify the spent composite solvent recovered in step b) by removing at least water, soiling.

In an advantageous embodiment, the elimination of insoluble soils is carried out by filtration on filtering means selected from the group consisting of button (or pin) filters, carbon filters and their combinations. This filtration is constant from the beginning to the end of the cycle of dry cleaning. The spent composite solvent thus filtered is subjected to fractional distillation. This fractional distillation is preferably carried out under reduced pressure, so as to eliminate a head fraction F1, on the one hand, and to collect an intermediate fraction F2, on the other hand.

F1 overhead fraction represents less than 15% w / w _S oivant spent composite and contains at least water and one or more azeotrope formed between the water and one or more components of the composite solvent. The F1 head fraction may also contain one or more components or part of one or more components of the composite solvent distilling at the same time as the water without necessarily forming azeotropes with the water.

Note: the expression "w / w composite spent _SO " means that the percentage is calculated with respect to the total weight of the spent solvent to be treated by fractional distillation.

The intermediate fraction F2 represents more than 75% w / w _S and composite oivant used preferably contains the composite solvent dry cleaning decreased by at least a portion, by weight, of one or more of its components, which portion was removed, for example, with the F1 head fraction and / or was lost in the bottoms fraction as explained below.

From a safety point of view, the bottom fraction of fractional distillation is usually not recovered. It is removed from the distillation unit and transferred to a tank for further processing. This bottoms fraction may contain insoluble soils and / or soluble soils. It may also contain another part, by weight, of one or more components of the composite solvent, or even one or more components of the composite solvent whose boiling point is too high even under reduced pressure, such as antioxidants, disinfectants and surfactants that are optionally included in the composition of the dry cleaning composite solvent. The treatment step c), preferably by filtration followed by fractional distillation, may be carried out during or in parallel with the dry cleaning cycle referred to in step a). By way of example, in the case of the preferred composite solvent S developed by the Applicant (see above), and contaminated with 5% w / w _S composite composite used water:

the fraction fraction F1 removed by fractional distillation in stage c) distils at a temperature below 82 ° C. and at a pressure of 65 mbar (or at a temperature of between 20 ° C. and 121 ° C. under 267 mbar) and comprises at least water, dipropylene glycol monomethyl ether, and optionally an amphiphilic solvent A 'corresponding to the following formula: R' -O-C3H6-OH (Γ) in which R 'represents an alkyl group C ₃ or C ₄ . This F1 head fraction may furthermore comprise a <20% fraction of F1 head in dibasic ester depending on the conditions chosen for the fractional distillation. It represents less than 15% w / w composite solvent S usé and,

the intermediate fraction F2 collected by fractional distillation in step b) distills at a temperature above 83 ° C, preferably between 83 ° C and 140 ° C, under a pressure of 65 mbar. This intermediate fraction F 2 represents more than 75% w / w composite solvent S used, preferably more than 95% w / w composite solvent S used

By way of example of amphiphilic solvent A ', mention may be made of propylene glycol mono-n-butyl ether, propylene glycol mono-isobutyl ether, propylene glycol mono- tert-butyl ether and mono-n-butyl ether. propylene glycol propyl ether, propylene glycol mono-isopropyl ether and mixtures thereof.

The intermediate fraction F2 collected in step c) therefore has a composition which is different from that of the composite solvent used for the dry cleaning. To be able to use this fraction F2 in a new cycle of dry cleaning of textile articles, it is necessary to rebalance its composition.

In practice, the intermediate fraction F 2 (or recycled composite solvent) is transferred from the treatment unit to a storage tank in which its composition will be completed by incorporating at least the part, by weight, of the component or components which has been lost in step c).

By way of example, in the case of the preferred composite solvent S, the part to be incorporated in the composition of the recycled composite solvent (here intermediate fraction F 2) in step d) comprises at least dipropylene glycol monomethyl ether, and the optionally one or more amphiphiles A having the following formula R- (O-C3H6) n -OH (I) in which n is an integer equal to 1 or 2, R represents a C ₃ or C ₄ alkyl group . The portion, by weight, to be incorporated into the composition of the recycled composite solvent may further comprise one or more dibasic esters B and / or one or more additional components.

The treatment and rebalancing cycle represented by steps c) to e) described above is completely automatic and can be carried out during or in parallel with the dry cleaning phase of textile articles.

In the case of a treatment of the composite solvent by fractional distillation, it may be useful to reprocess the fraction head F1 eliminated during the fractional distillation to, on the one hand, to minimize the volume of the rejects of solvents, and, of on the other hand, to compensate for any lack of selectivity in the fractional distillation. For this purpose, the present invention proposes to recover the F1 head fraction after N dry cleaning cycles and to subject it to fractional distillation. Typically, this second fractional distillation is carried out so as to eliminate a head fraction F'1, and to recover a fraction F'2, which fraction F'2 is intended to be added, before step e) of rebalancing, to the intermediate fraction F2 collected after the dry cleaning cycle N. Of in general, the overhead fraction F'1 eliminated during this second fractional distillation contains a predominant quantity of water. The number N of dry cleaning cycles after which the removed head fraction F1 is to be recovered, can be determined by those skilled in the art depending on the composition of the composite solvent used and the selectivity of the fractional distillation. By way of non-limiting example, in the case of the preferred composite solvent S of the invention, the recovered F1 head fraction is fractionally distilled off every N dry cleaning cycles, for example every 10 to 50 cycles of dry cleaning, preferably every 20 to 30 cycles of dry cleaning. In this case, the fraction F'1 containing a preponderant quantity (> 50% w / ntraction) of water, distills at a temperature below 100 ° C. under 200 mbar and the fraction F'2 to be added to the fraction at F2 distills under pressures less than 70 mbar.

Installation for the dry cleaning of textile articles and for the regeneration of the spent composite solvent.

Figures 1 and 2 attached diagrammatically, according to two preferred embodiments, the organization of an installation according to the invention. This installation comprises at least one dry cleaning chamber (1) configured to mix, during a cleaning cycle, the textile articles to be cleaned with the composite solvent; a reservoir (5) for storing the clean composite solvent; a treatment device (8) for the composite solvent used to recycle the latter at least in part; and a rebalancing device (9) of the recycled composite solvent composition. By way of example, the tank (5) can be of a capacity of 120 liters in the case of a cleaning installation provided for 12 to 14 KG of textile articles to be cleaned.

Advantageously, a perforated drum (2) made of stainless steel for receiving the textile articles to be cleaned is rotatably mounted in the cleaning chamber (1). Typically, this drum (2) is made of stainless steel, has a capacity of 200L to 1500L and can receive from 9 kg to 70 kg of textile articles to dry clean. The rotational speed of the drum during a cleaning operation can vary, for example, from 1 rpm to several hundred rpm, preferably from 300 rpm to 600 rpm, preferably from 400 rpm to 500 rpm. 500 rpm.

The cleaning chamber (1), which is otherwise sealed, has at least one opening (20) for the placement of the textile articles to be cleaned in the perforated drum (2), this opening (20) being closable (hermetically) by a door or porthole; an orifice (3) connected to an introduction line (4) of the clean composite solvent which is placed in the storage tank (5); and an orifice (6) connected to a recovery line (7) of the spent composite solvent after a cleaning cycle.

The introduction pipe (4) is, in general, provided with at least the following means (not shown in FIG. 1):

a feed pump for feeding the composite solvent stored in the tank (5) to the cleaning chamber (1),

heating means, such as a heat exchanger, for increasing the temperature of the composite solvent for cleaning the textile articles at a temperature above room temperature, for example at a temperature between 25 ° C and 50 ° C ,

means, such as a fan, for introducing a stream of hot air (heated to a temperature above 40 ° C, preferably between 65 ° C to 75 ° C) into the cleaning enclosure (1) for to dry the cleaned textile articles.

After a dry cleaning cycle, the spent composite solvent is discharged through the recovery line (7). The latter is generally provided with at least:

a drain valve (not shown) controlled by a control device, an evacuation pump (not shown) able, on the one hand, to suck up the spent composite solvent, and optionally the residual composite solvent evaporated and condensed, from the enclosure (1), and on the other hand to transfer it to the treatment device (8) for at least partial recycling.

According to a preferred embodiment, the treatment device (8) is equipped with a filtration device (12), such as a button filter (or pins), an activated carbon filter or their combination, to clarify the spent composite solvent, in particular for ridding it of insoluble soiling; and a fractional distillation unit (13) operable to allow, on one hand, the elimination of a F1 overhead fraction comprising less than 15% w / w _S oivant composite used and containing at least the water, one or more azeotropes formed between the water and one or more components of the composite solvent; and, on the other hand, recycling of an intermediate fraction F2 representing more than 75% w / w _S and composite oivant worn containing the composite solvent dry cleaning decreased by at least one part by weight of a or several of its components, which part was lost in the treatment step c).

The fractional distillation unit (13) comprises at least the following means (not shown in FIG. 1): a distillation column equipped at its base with a boiler and at its head a condenser associated with a vacuum pump . Said boiler is fed with spent composite solvent through line (12a) and has the function of vaporizing at least part of the spent composite solvent. The operating conditions of said boiler are conventional and are a function of the spent composite solvent to be treated by fractional distillation, the latter being able to be implemented by temperature gradient under a constant pressure, or by pressure gradient and temperature.

By way of example, in the case of the preferred composite solvent S (see above), the temperature in the boiler can be maintained at a value below 250 ° C., for example at a value ranging from 25 ° C. to 180 ° C. C, preferably from 120 ° C to 160 ° C under a reduced pressure of 65 mbar. The fractional distillation unit (13) has at least a first outlet for the discharge according to the arrow F1 of the head fraction F1 to an evacuation tank (or fluid container) (30) for further processing in view a reuse, and a second output for the recovery according to the arrow F2 of the intermediate fraction F2 which is sent by the pipe (7a) to the buffer tank (10) in which it must be rebalanced for use in another cycle of dry cleaning. By way of example, the capacity of the buffer tank (10) can be 60 liters in the case of a cleaning installation provided for 12 kg to 14 kg of textile articles.

According to a preferred variant of the invention, the discharge tank (30) containing the head fraction F1 comprises a pipe (300) connected to an injection device (301) for injecting, after N cleaning cycles. to dry, the fraction F1 in the fractional distillation unit (13) to separate it into at least two fractions: a head fraction F'1 to be eliminated, and a fraction F'2 to be added, before the rebalancing step e), at the intermediate fraction F2 collected after the dry cleaning cycle N. More specifically, the device (9) for balancing the composition of the recycled composite solvent consists of at least:

the buffer tank (10) equipped with at least one recycled composite solvent feed inlet (10a) (intermediate fraction F2), at least one feed inlet (10b) in at least the portion, by weight, the component or components of the composite solvent to be introduced into the buffer tank (10) in order to rebalance the composition of the recycled composite solvent (or intermediate fraction F2), and at least one outlet (10c) of the recycled and rebalanced composite solvent, this outlet (10c) being connected to the storage tank (5) of the composite solvent for dry cleaning,

a dosing pump (14) of the (predetermined) quantity of the component (s) of the composite solvent to be introduced into the buffer tank (10) at through said inlet (10b), this pump is connected upstream to at least one storage tank (1 1) of one or more components of the composite solvent. For example, the tank (1 1) can be of a capacity of 20 liters in the case of a cleaning installation provided for 12 to 14 KG of textile articles to be cleaned.

The rebalancing device (9) can be provided with an analyzer (15) equipping the buffer tank (10) and making it possible to analyze the physical and / or chemical characteristics of the recycled composite solvent, so as to determine the quantity of the components of the composite solvent to be introduced into this buffer tank (10). The analyzer (15) consists, for example, of a weight detector; a liquid level detector; a UV, Visible or Infra-Red (IR) spectrometer; a refractometer; or else, said analyzer (15) being connected to a computer server of the type incorporating a processor and a memory in which are stored one or more computer programs. These include instructions that, when executed by the processor, implement the features defined below. The analyzer (15) analyzes the physical and / or chemical characteristics of the recycled composite solvent and transfers this data to the server. The latter compares the characteristics determined for the recycled composite solvent contained in the buffer tank (10) with those of the clean dry cleaning composite solvent. It is then possible to determine the quantity of the component (s) to be taken from the storage tank (s) (1 1) and to be introduced into the buffer tank (10). The analyzer (15) thus transmits a suitable control setpoint to the metering pump (14).

According to another variant of the invention (FIG. 2), the fractional distillation unit (13) is provided with a collection container (31) configured to initially receive the head fraction F1 before being discharged according to the invention. F1 arrow towards the evacuation tank (30), then in a second time, the intermediate fraction F2 before its sending according to arrow F2 to the buffer tank (10). The collection vessel (31) has a lowering point (31 a) at its lower part, through which the head fraction F1 and the intermediate fraction F2 are discharged to their respective tanks. According to this variant, the collection container (31) is equipped with an analyzer (15a) making it possible to analyze the physical and / or chemical characteristics of the F1 head fraction of the F1 head fraction or the F 2 fraction before their evacuation of said collection container (31), so as to determine as described above the amount of the component or components of the composite solvent to be introduced into the buffer tank (10). The analyzer (15a) may be of the same type as the analyzer (15) described above. According to this variant, the buffer tank (10) can also be equipped with the analyzer (15a) (option not shown). According to another variant (not shown) only the buffer tank (10) is equipped with the analyzer (15a). The various pumps equipping the installation of the present invention are for example centrifugal, peristaltic or vortex type pumps. And, the various pipes of the installation are provided with valves whose arrangement makes it possible to circulate the fluids correctly. These different pumps and the different valves can be controlled independently of each other to ensure optimal operation of the installation according to the invention.

The installation of the present invention is advantageously a semi-industrial installation (hospitals, hotels, etc.) or for a wash-room or an installation for domestic use.

Note:

The composite solvents exemplified in the present description (dipropylene glycol mono-methyl ether, amphiphilic solvent A and amphiphilic solvent A ') can exist in the form of positional isomers, optical isomers or their combination. The term "and / or" used in certain passages of the present description includes the meanings and, or, as well as all other possible combinations of elements connected to this term. It goes without saying that different variants and improvements can be made to the cleaning installation without departing from the scope of the invention. So :

the treatment device, in particular the distillation unit, can be arranged outside the cleaning installation, and if necessary be connected to one or more other cleaning facilities.

the boiler of the distillation unit may be provided with a draw-off point at its lower part for the recovery of the heavy fractions which have not distilled, for subsequent treatment. Examples

Example 1 - Preferred Dry Cleaning Composite Solvents

The preferred composite solvents 1 to 6 of the invention are prepared from the ingredients indicated in the table below by any method known to those skilled in the art.

Weight share (w / w _S composite income) in%

Ingredients Examples:

1 2 3 4 5 6 monomethyl ether of dipropylene glycol (DPM),

mono- / 7-butyl ether 9 propylene glycol (PnB)

dipropylene glycol mono- / 7-butyl ether (DPnB)

dibasic ester (DBE) 22 20 10 30 12 22 The DBE dibasic ester used in Examples 1 to 6 is Rhodiasolv® RPDE marketed by Rhodia®.

Anhydrous (colorless), clear and colorless composite solvents 1 to 6 are obtained which are chemically stable. These composite solvents can be stored for more than 1 year or more than 2 years, at a temperature below 40 ° C, in closed containers and protected from air and light. They bring, in particular, the following properties:

compatibility with respect for the environment, human and animal health, and safety at work in dry-cleaning establishments, flash points: above 75 ° C,

Kauri-Butanol index: greater than 70

anhydrous (non-aqueous) and dilutable in water with miscibility greater than 40% v / v in water.

Example 2 - Effects of composite solvents 1 to 6

The effect of composite solvents 1 to 6 as dry cleaning solvents was studied on a panel of fabrics (10 cm x 10 cm) made of various fibers as well as on accessories frequently found on textile articles. A first study focused on the observation of tissue deformation and discoloration and the second on the effectiveness of stain cleaning.

To perform these tests, the fabrics were impregnated (by immersion) and mechanically stirred in the composite solvents 1 to 6 for 10 min and then dried in a ventilated oven at 70 ° C.

Results: 1) Deformations, discoloration and deterioration of the packings: Tests carried out on various fabrics of polyester, cotton, linen viscose, acrylic, wool, acetate, elastane, silk have shown that the fabrics are well washed, dried easily have no odor after drying and keep their measure well even in the case of wool (deformation less than 0.2 mm). The experiment on textile parts has shown that with these composite solvents the fabric is much less dry than with perchlorethylene, and provides a good glide which makes ironing easier, and reduces the risk of felting in machines. Elastic textiles have kept their property expandable. The best dry cleaning results were obtained with composite solvents 2 and 4.

Concerning the discoloration, we observed a slight disgorging in the case of the composite solvent 3 without redeposition of it on the other tissues. In the case of other composite solvents the fade resistance is good or even better than that of perchlorethylene when comparing dry washed fabrics with reference samples.

2) Behavior on the fittings:

The effect of composite solvents 1 to 6 as a dry cleaning solvent has been studied on linings frequently encountered on textile articles such as buttons, plastic or metal zippers and glued flakes.

The tests on gaskets (buttons and accessories) have shown that composite solvents I to 6 give identical or better results than perchlorethylene with preference for composite solvents 1, 2, 5 and 6 which more respect these elements.

3) Behavior on stains:

The tissues studied contained soiling caused by the following contaminants: olive oil, chocolate (Nutella®), mayonnaise, lipstick, red wine, ink and were compared to perchlorethylene and hydrocarbons. These tests were carried out without the use of intensifier (surfactant). The results of these tests showed that:

the composite solvents of Examples 1 to 6 made it possible to very easily clean greasy stains without the use of additives.

the composite solvents of Examples 1, 2, 4 and 6 are particularly very effective for the dry cleaning of stains due to butter or olive oil, which stains are no longer visible at the end of the cleaning process .

the composite solvents of Examples 1 and 2 have in particular been very effective for dry cleaning, especially on stains due to chocolate, lipstick and wine, which spots have become less visible after the cleaning process. unlike perchlorethylene which leaves larger spots.

The arrangement of the various elements and / or means and / or steps of the invention, in the embodiments described above, should not be understood as requiring such an arrangement in all implementations. In any case, it will be understood that various modifications may be made to these elements and / or means and / or steps, without departing from the spirit and scope of the invention.

Claims

1. Process for dry cleaning textile articles using a composite solvent comprising several components and recycling the used composite solvent for reuse, said process comprising:

a) a dry cleaning cycle comprising bringing the textile articles to be cleaned into contact with the composite solvent,

b) the recovery of the spent composite solvent contaminated by water and dirt at the end of the dry cleaning cycle,

c) treating the spent composite solvent so as to eliminate at least water and dirt,

d) recycling at least part of the composite solvent treated in step c) with a view to using it for another dry cleaning cycle,

said process being characterized in that it further comprises a step e) of rebalancing the composition of the recycled composite solvent in step d) in which:

the part of the component(s) of the composite solvent which was lost during step c) is determined,

at least the determined portion of the component(s) of the composite solvent which was lost during step c) is incorporated into the composition of the recycled composite solvent in step d).

2. Method according to claim 1, characterized in that in step c) the treatment of the spent composite solvent is carried out by fractional distillation

3. Process according to claim 2, characterized in that the fractional distillation is carried out so as to: eliminate a head fraction F1 representing less than 15% w/w _S oivant spent composite and containing at least water and one or more azeotropes formed between water and one or more components of the composite solvent, and

collect an intermediate fraction F2 representing more than 75% w/w _S oivant J used composite and containing the dry cleaning composite solvent reduced by at least one part, by weight, of one or more of its components, which part was lost in processing step c).

4. Method according to claim 2 or 3, characterized in that in step c)0 prior to the fractional distillation, the spent composite solvent is filtered to eliminate insoluble dirt.

5. Method according to one of claims 1 to 4, characterized in that the composite solvent used for dry cleaning textile articles comprises at least:

from 40% to 80% w/psovant composite of dipropylene glycol monomethyl ether, from 5% to 40% w/ _w Soovant composite of an amphiphilic solvent A corresponding to the following formula: R-(0-C3H6) _n - OH (I) in which n is an integer equal to 1 or 2, and R represents a C ₃ or C ₄ alkyl group,

0 - from 10% to 40% w/psovant composite of a dibasic ester B selected from the group comprising dimethyl succinate, dimethyl glutarate, dimethyl adipate and mixtures thereof, and

from 0% to 10% p/psovant composite of additional components. 5

6. Method according to one of claims 1 to 5, characterized in that the spent composite solvent to be recycled is contaminated by at least 0.5% w/ _w of used e3U composite.

7. Method according to one of claims 5 to 6 taken in combination with claim 3, characterized in that the overhead fraction F1 eliminated by fractional distillation in step c) distills at a temperature below 82°C and under a pressure of 65 mBars and comprises at least water, dipropylene glycol monomethyl ether, and where appropriate an amphiphilic solvent A' corresponding to the following formula: R'-0-C3H6-OH (Γ) in which R ' represents a C ₃ or C ₄ alkyl group.

8. Method according to one of claims 5 to 7 taken in combination with claim 3, characterized in that the intermediate fraction F2 collected by fractional distillation in step c) distills at a temperature above 83°C and under a pressure of 65 mBars.

9. Method according to one of claims 5 to 8, characterized in that the part to be incorporated into the composition of the recycled composite solvent in step d) comprises at least dipropylene glycol monomethyl ether, and where appropriate a solvent amphiphile A' corresponding to the following formula R'-0-C3H6-OH (Γ) in which R' represents a C3 or C ₄ alkyl group.

10. Method according to one of claims 1 to 9, characterized in that it further comprises a step consisting of analyzing the composition of the recycled composite solvent and determining the quantity of the component(s) to be incorporated into said composition with a view to rebalance it.

1 1. Method according to claim 3 or 7, characterized in that the head fraction F1 eliminated in step c) is recovered in an evacuation tank, then, after N dry cleaning cycles, is subjected to a fractional distillation, which fractional distillation is carried out so as to eliminate an overhead fraction F'1, said overhead fraction F'1 containing a preponderant quantity of water, and recover a fraction F'2, said fraction F'2 being intended to be added, before rebalancing step e), to the intermediate fraction F2 collected after the dry cleaning cycle N.

12. Installation for dry cleaning textile articles using a composite solvent comprising several components, said installation comprising:

a dry cleaning chamber (1) configured to mix, during a cleaning cycle, the textile articles to be cleaned with the composite solvent,

a device (7) for recovering the spent composite solvent after a cleaning cycle,

a treatment device (8) for removing water and dirt and recycling at least part of the spent composite solvent for use in another dry cleaning cycle,

said installation being characterized by the fact that it further comprises a device (9) for rebalancing the composition of the recycled composite solvent, which device (9) comprises:

a means for determining the part of the component(s) of the composite solvent which was lost during step c),

means for incorporating into the composition of the composite solvent recycled in step d) at least the determined portion of the component(s) of the composite solvent which was lost during step c).